Pythagasaurus is the latest short film from the commercials department of Wallace and Gromit-creators Aardman. It tells the story of two not-too-bright cavemen – voiced by Bill Bailey and Martin Trenaman – who decide that the only way to save their hut from an erupting volcano is to enlist the help of the maths-loving dinosaur of the title.

Alongside spots for the likes of BT, Cheerios and Nokia, the department commissions directors it works with to produce shorts to encourage them to experiment and broaden their range. These films are then worked on the whole team in the department – from modellers and animators to TDs – in between commercial projects (which is why it took years to complete).

“I wanted my film to be a mixture of 2D and 3D elements and to be richly detailed, as I'd never really tried either of those things before,” says director Peter Peake. “I really feel like you're missing a trick in animation if you don't let your mind run riot. It's one of the reasons I love it.”

Peter says that creating an obviously prehistoric world is easy as it requires only a few visual cues, giving him a lot of room to style the environment and characters any way he wished. So while the two central characters (above) are clearly cavemen, Peter wanted to give them a look that played along with the humorously incongruous world that they live in that contains both mud huts and mini-breaks in Cornwall.

“I wanted them to look a little bit too well-groomed to be hanging around in prehistoric times,” he says. “It was a bit like two builders had decided to dress up as cavemen for their local Amateur Dramatics Society.”

Peter had a clear idea of how he wanted the Pythagasaurus (above) to look from the very beginning, adding rubber arms to a set square-shaped body. He says that the team spent time “playing around with textures trying to marry together the scaly, reptilian skin on his head with his transparent plastic body – but I didn't think it was a bad thing if he looked cobbled together. The more ridiculous he turned out the better.”

While Peter was making a conscious effort to work outside of Aardman’s “house style”, the mouths of the cavemen and dinosaur drew on shapes from Aardman’s claymation heritage. He thinks that “they work so well, they're really funny and to be honest it's probably a little ingrained.”

Mouth shapes for phonemes (basic building blocks of speech) for the cavemen and Pythagasaurus

As a ‘downtime project’, the crew could only work on it when they weren’t working on a commercial project, so there were long pauses in production – even being put on the shelf for a couple of years during a particularly busy period. As well as being frustrating for Peter, it also caused a few workflow issues. He notes that with staff moving on – the four-minute film ended up having three CG supervisors, for example – it would often take a few days for new artists and animators to get up to speed, delaying the finishing date further.

“Having said that, the crew were incredibly skilled at picking up the pieces and where possible we tried to keep the same people working on the film throughout the production,” says Peter. “We tried to limit too many people passing the film around to avoid continuity problems, even if this meant waiting for some time for a particular person's availability – and I think this really paid off.”

An initial sketch for the world of Pythagasaurus

Peter directed stop-motion animation in the days before widespread use of CG. While he still has a passion for both, he finds stop-motion much easier to direct. He notes that stop-motion requires a clear vision of the exact shots you want before you capture the first frame – whereas CG offers much more flexibility. However, he sees his background in stop-motion as invaluable for learning how to compose shots and direct performances.

“One of the main things I love about stop-motion is the tactile quality that it has,” he says, “the feeling that you could almost reach out and grab the models and the scenery and you can relate to the materials that they're made out of. I think this has influenced the way I approach the CG look to some extent.”

However, Peter isn’t trying to merely trying to use CG as a way to get round stop-motion’s arduous production process. He says that “it's nice if the modelling, texturing and lighting can capture some of these qualities – but at the same time I don't really buy into one technique trying to look like another. I'm a firm believer they should play to their individual strengths.”